"Magick" is the effete spelling of magic, now with a "k" for extra phear! "Magick" is used to demonstrate that the user is really cool; 1337; and clued in to a centuries-old tradition of real, authentic, honest-to-goodness magic, and not merely a deluded poseur.

Supporters of this aberrant spelling will be all "blah blah Jew blah blah Crowley blah blah blah", but I'm all like "talk to the hand".

Wiccan: "And so, after astral projeckting and ascending to the Nth plane, I ckame in ckontackt with the divine manifestation of the natural being. I was empowered with a sense of ckonfidencke and felt my powers grow. I beckame one with the universe. When I wocke up, my cklothes were missing and my ass hurt. Did I mention I'm bi and I licke Fall Out Boy?"

New Ager/Druid: "I strive to beckome one with the universe, and lose my ego in the greater depths of ckosmick being. My earthly attachments will dissolve and I will transcend this plane of existence, like that one summer solstice at Stonehenge when we toock three hits of E each and really ckonneckted with the earth...speaking of which, got any herb?"